大尺度变化梯度膜过滤系统气固流体动力学特性和临界分离机理研究

项目名称： 大尺度变化梯度膜过滤系统气固流体动力学特性和临界分离机理研究

项目编号： No.U1504217

项目类型： 联合基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 李海霞

作者单位： 河南理工大学

项目金额： 27万元

中文摘要： 随着人们和社会对PM2.5 和PM10 等污染物排放标准要求的提高，高温气体膜过滤技术在众多工业过程中得到了广泛应用。滤芯失效影响过滤器长周期稳定运行，降低过滤能效。本项目通过理论分析、数值模拟和实验方法，研究跨尺度膜过滤系统气固流体动力学特性和临界分离机理。采用欧拉-欧拉双流体模型和k-ε模型，将幂律非线性渗流模式和动态渗透率模式，作为气体在微尺度滤饼区域和滤膜区域流动的边界条件，建立跨尺度膜过滤系统多场耦合渗流多相流模型。应用相似理论对过滤系统量纲分析，得到无量纲通用关联式，揭示过滤机理，探索膜过滤临界条件。在临界分离条件下，研究膜过滤系统流场形态、滤饼形成和脱落规律，计算滤芯所受应力，预测滤芯使用寿命，提高膜过滤系统能效。研究成果为提高膜过滤系统能效、确保长周期安全运行奠定理论基础，并为膜过滤系统优化设计、性能分析提供研究思路，也为其他类似多场耦合过滤系统的优化提供参考。

中文关键词： 跨尺度模型；膜过滤；气固多相流；多场耦合；渗流

英文摘要： Hot gas membrane filtration has been attracting more and more attention in a wide variety of processes over the last years. Main reasons for that are higher demands on emission levels, such as PM 10 and PM 2.5.The filter failure affects stable operation of the long period of the membrane filtration, reducing the filtration efficiency. The project studies the dynamics characteristics of the gas-particle flow and the critical separation conditions in cross-scale membrane filtration system using the method of theoretical analysis, numerical simulation and experimental measurement. The Euler-Euler two-fluid model and k-ε model are used to establish multi-field coupling seepage multiphase flow model for cross-scale membrane filtration system. The nonlinear flow of power-law model and the dynamic permeability model are added into the seepage multiphase flow model as the boundary conditions of the membrane area and filtration cake area. The similarity theory is applied to dimensionally analysis the controlling equation to reveal the filtration mechanism and to determine the membrane critical operating conditions. The experimental measurement and simulation method are used to study the flow field, the characteristic of cake formation and shedding in the membrane filtration system under critical conditions to improve membrane filtration system energy efficiency and ensure the long-cycle security run. The research result can laid a theoretical foundation for membrane filtration system to optimize design, performance, and also provides reference for other similar multi-field coupling filter system to optimize design.

英文关键词： Cross-scale model;membrane filtration;gas-solid multiphase flow;multi-field coupling;percolation